Car names beginning with a d?

Depends if you're asking for makes or models. Manufacturers include

Daktari, Datsun (aka Nissan), Daytona, Deuce Customs, Devaux, DRB sports cars, Dacon, Dardo, Democrata, Davis, Detroit-chatham, Dominion, Diamond Arrow...

A full list would take quite a while. I highly recommend checking the link attached.